Automatically self-adjustable electric switch



July 4, 1967 B. A. SCHWARTZ 3,329,794

AUTOMATICALLY SELF-ADJUSTABLE ELECTRIC SWITCH Filed Oct. 23, 1965 may INVENTOR. BERNARD A. SCHWARTZ United States Patent 3,329,794 AUTOMATICALLY SELF-ADJUSTABLE ELECTRIC SWITCH Bernard A. Schwartz, Franklin Lakes, NJ. The Budd Company, 411 W. Main St, Wyckoff, NJ. 07481) Filed Oct. 23, 1965, Ser. No. 503,242 9 Claims. (Cl. 200170) This invention relates to electric switches. More particularly, it relates to an improved electric switch that is sensitive and automatically self-adjustable.

It is an important object of this invention to provide an electric switch which permits great sensitivity of application.

It is another object to provide a switch in accordance with the preceding object which has an improved operating lifetime, i.e., the switch elements therein are selfadjusting in response to wear.

It is a further object to provide a switch in accordance with the preceding objects which is adaptable to a multiplicity of diverse applications.

Generally speaking and in accordance with the invention, there is provided an electric switch comprising a plurality of fixed contacts adapted to have electrically conductive leads connected thereto which are connected to the terminals of an electric source, a pair of adjacently disposed members and tensioning means afiixed to the members normally urging the members toward each other. One of the members is disposed in juxtaposition with and spaced from the fixed contacts, a recess being provided in the one contact for receiving a movable contact therein in a given plane. There are further included a movable contact and means associated with the one member and extending through the recess for mounting the movable contact thereon, the movable contact being received in the recess and being configured to movably make electrical contact with the fixed contacts in response to the urging action of the tensioning means. Means are also provided for pivotally mounting the one member to enable its rotation in plane substantially perpendicular to the aforesaid given plane to remove the movable contact from electrical connection with the fixed contacts.

For a better understanding of the invention together with other and further objects thereof, reference is had to the following description taken in conjunction with accompanying drawing, and the scope of the invention is pointed out in the amended claims.

In the drawing,

FIGURE 1 is a three dimensional view of an illustrative embodiment of an electric switch constructed in accordance with the principles of the invention;

FIGURE 2 is an end elevational view of the embodiment depicted in FIG. 1;

FIGURE 3 is a bottom view of the embodiment shown in FIGS. 1 and 2;

FIGURE 4 is a section taken along lines 4-4 of FIG. 2 looking in the direction of the arrows; and

FIGURE 5 is a section taken along lines 5-5 of FIG. 3 looking in the direction of the arrows.

Referring now to the drawing, the embodiment of the switch depicted therein suitably comprises a pair of members 12 and 14 in spaced adjacent relationship which are shown as being alligator jaws. Members 12 and 14 suitably comprise a dielectric material such as a plastic. Members 12 and 14 are received in a rectangular base 20 which suitably also comprises a dielectric material. As seen in FIG. 1, member 14 extends partly into base 20 whereas the base of member 12 terminates in an extension 22 whose bottom surface is flush with the bottom surface of base 20. With such arrangement, the inner wall of base 20 and the inner wall of extension 22 enables the providing of a spacing element 24 therebetween, also consisting of a dielectric material, which insures that members 12 and 14 are always maintained spaced from each other at least a given amount.

A coiled spring 18 suitably anchored at each end thereof on pins which may be respectively provided within transverse openings 13 and 15 through members 12 and 14 and disposed in channels in members 12 and 14 functions to urge members 12 and 14 toward each other, a minimum spacing therebetween being provided through the arrangement of spacing element 24. A transverse opening 28 is provided through member 14 and base 20 wherein there is provided a rod 16 or like element to enable member 14 to be rotated thereabout on a horizontal axis in a counterclockwise direction from the aspect as viewed in FIGS. 2 and 5, such rotation being effected against the normal action of spring 18 of urging members 12 and 14 toward each other.

Provided in member 14 is a transverse recess 30, suitably of parallelepiped configuration wherein there is received a movable electrical contact 32 which may suitably be a planar structure comprising an electrically conductive material such as copper. Contact 32 is suitably maintained positioned in recess 30 by a screw 34 which extends into member 14 and through recess 30, contact 32 being suitably mounted on screw 34.

The fixed contacts of switch 10 comprise respective terminal lugs 36 and 38 to which are connected conductors 37 and 39, conductors 37 and 39 being adapted to be connected to the diiferent terminals of an electrical source. The fixed contacts of switch 10 further comprise terminals strips 40 and 42 which are associated with terminal lugs 36 and 38 respectively, lug 36 and strip 40 being interconnected by an element 43 extending through spacing element 24, and lug 38 and strip 42 being interconnected by an element 45 extending through spacing element 24, lugs 36 and 38, strips 40 and 42 and elements 43 and 45 all also suitably consisting of a conductive material such as copper.

The position of screw 34 and the dimensions of structure 32 are so chosen whereby the bottom edge of structure 32 bears against strips 40 and 42 whereby the electric circuit is closed between the fixed contacts. In other words, the switch normally assumes the closed position.

To go from the closed to the open position, i.e., to break the contact between structure 32 and strips 40 and 42, member 14 is rotated in the counterclockwise direction about rod 16 as shown in FIGS. 2 and 5 against the tensioning action of spring 18. Such rotation may be eifected automatically, for example, by the camming action of a member being preceded through opening 47, or by any means, manual or mechanical which causes the rotation of member 14 about rod 16.

It is readily seen from the foregoing that the degree of motion required of member 14 to open the contact between structure 32 and strips 40 and 42 depends upon the location of the horizontal rotational axis provided by rod 16, such location being chosen in accordance with sensitivity requirements. In any event, the mechanical advantage provided by the rotational arrangement of member 14 enables extreme sensitivity in the opening of the switch.

In the event that one end portion of the lower edge of structure 32 should become worn sooner or more worn than the other end portion, the free mounting of structure 32 on screw 34 enables it in this contingency to rotate on screw 34 whereby the lower edge of structure 32 always makes contact with terminal strips 40 and 42.

It is thus seen that in accordance with this invention there is provided an extremely sensitive switch whose movable contact is automatically self-adjusting to insure a constant normally closed state of the switch despite CD uneven wear of the contacting edge of the movable contact.

While there has been described what is considered to be a preferred embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention and it is, therefore, aimed in the appended claims to cover all such changes and modifications as fall within the spirit and scope of the invention.

What is claimed is:

1. An electric switch comprising a plurality of fixed contacts adapted to have electrically conductive leads connected thereto which are connected to the terminals of an electric source, a pair of adjacently disposed members, tensioning means affixed to said members and normally urging said members toward each other, one of said members disposed in juxtaposition with and spaced from said fixed contacts, a recess in said one member for receiving a movable contact therein disposed in a given plane, a movable contact, means associated with said one member and extending through said recess having said movable contact freely rotatably mounted thereon, said movable contact recessed in said recess and configured to normally make electrical contact with said fixed contacts and means pivotally mounting with respect to said fixed contacts said one member and said movable contact thereon to enable the rotation with respect to said fixed contacts of said one member and said movable contact thereon in a plane substantially perpendicular to said given plane to remove said movable contact from electrical connection with said fixed contacts.

2. An electric switch comprising a plurality of fixed contacts adapted to have electrically conductive leads connected thereto which are connected to the terminals of an electric source, a pair of adjacently disposed members, spacing means associated with said members and maintaining said members spaced from each other at least a given distance, tensioning means affixed to said members and normally urging said members toward each other, one of said members disposed in juxtaposition within and spaced from said fixed contacts, a recess in said one member for receiving a movable contact therein disposed in a given plane, a movable contact, means associated with said one member and extending transversely through said recess having said movable contact freely rotatably mounted thereon, said movable contact disposed in said recess in said given plane and configured to normally make electrical contact with said fixed contacts, and means for pivotally mounting with respect to said fixed contacts said one member and said movable contact thereon to enable the rotation with respect to said fixed contacts of said one member and said movable contact thereon about a horizontal axis and in a plane substantially perpendicular to said given plane to remove said movable contact from electrical connection with said fixed contacts.

3. An electric switch comprising a base, a pair of adjacently disposed first and second members received within said base, spacing means disposed between said base and said first member for maintaining said members spaced from each other a given distance, said base, said spacing means and said members comprising a dielectric material, a plurality of fixed electrical contacts on said spacing means adapted to have electrical leads connected thereto for connection to the terminals of an electrical power source, said second member having a surface opposed to and spaced from said fixed contacts, a recess extending from said surface into said second member disposed transversely to said contacts, a screw extending into said second member and transversely through said recess, a planar movable electric contact disposed in said recess and mounted on said screw to be freely rotatable thereon, an edge of said movable contact normally making contact with said fixed contacts, a rod extending through said base and said second member substantially parallel to the plane of said movable contact, said second member being rotatable about said rod on a horizontal axis and in a plane substantially perpendicular to the plane of said movable contact, and tensioning means connected to said members respectively for normally urging said members toward each other.

4. An electric switch as defined in claim 3 wherein each of said fixed contacts comprises a conductive terminal strip on one surface of said spacing means opposing said surface of said second member, a conductive lug on the opposite surface of said spacing means, and a conductive element connecting said strip and said l-ug, said leads connected to said lugs and wherein said movable contact comprises an electrically conductive material.

5. An electric switch as defined in claim 4 wherein said members comprise a pair of like jaws having registered adjacent cutout portions which define a space for receiving a camming device for effecting automatic opening of said switch from its normally closed position.

6. A self-adjustable switch adapted to compensate for contact wear and other variable conditions, comprising a plurality of fixed contact elements occupying a common plane and a movable contact element adapted to bridge said fixed contact elements, said movable contact element mounted for pivotal movement about two pivotal axes toward and away from said fixed contact elements, one axis being parallel to said common plane, the other axis being perpendicular to the first axis.

7. A self-adjustable switch in accordance with claim 6 wherein the movable contact element is spring-urged about the first-mentioned pivotal axis in the direction of said fixed contact elements.

8. A self-adjustable switch adapted to compensate for contact wear and other variable conditions comprising a first support, a plurality of fixed contact elements mounted on said first support and occupying a common plane thereon, a second support mounted on said first support for pivotal movement toward and away from said fixed contact elements, the pivotal axis being parallel to said common plane, and a movable contact element adapted to bridge said fixed contact elements, said movable contact element connected to said second support for pivotal movement relative to said fixed contact elements, the pivotal axis of said movable contact element being perpendicular to the pivotal axis of said second support.

9. A self-adjustable switch in accordance with claim 8, wherein the second support is spring-urged about its pivotal axis in the direction of the fixed contact elements.

ROBERT K. SCHAEFER, Primary Examiner.

H. 0. JONES, Assistant Examiner. 

1. AN ELECTRIC SWITCH COMPRISING A PLURALITY OF FIXED CONTACTS ADAPTED TO HAVE ELECTRICALLY CONDUCTIVE LEADS CONNECTED THERETO WHICH ARE CONNECTED TO THE TERMINALS OF AN ELECTRIC SOURCE, A PAIR OF ADJACENTLY DISPOSED MEMBERS, TENSIONING MEANS AFFIXED TO SAID MEMBERS AND NORMALLY URGING SAID MEMBERS TOWARD EACH OTHER, ONE OF SAID MEMBERS DISPOSED IN JUXTAPOSITION WITH SAID SPACED FROM SAID FIXED CONTACTS, A RECESS IN SAID ONE MEMBER FOR RECEIVING A MOVABLE CONTACT THEREIN DISPOSED IN A GIVEN PLANE, A MOVABLE CONTACT, MEANS ASSOCIATED WITH SAID ONE MEMBER AND EXTENDING THROUGH SAID RECESS HAVING SAID MOVABLE CONTACT FREELY ROTATABLY MOUNTED THEREON, SAID MOVABLE CONTACT RECESSED IN SAID RECESS AND CONFIGURED TO NORMALLY MAKE ELECTRICAL CONTACT WITH SAID FIXED CONTACTS AND MEANS PIVOTALLY MOUNTING WITH RESPECT TO SAID FIXED CONTACTS SAID ONE MEMBER AND SAID MOVABLE CONTACT THEREON TO ENABLE THE ROTATION WITH RESPECT TO SAID FIXED CONTACTS OF SAID ONE MEMBER AND SAID MOVABLE CONTACT THEREON IN A PLANE SUBSTANTIALLY PERPENDICULAR TO SAID GIVEN PLANE TO REMOVE SAID MOVABLE CONTACT FROM ELECTRICAL CONNECTION WITH SAID FIXED CONTACTS. 